A hand-held power tool such as a hammer of the type which has a main handle and an auxiliary handle and is designed to be operated with the main handle held with one hand and the auxiliary handle with the other hand is known. Such a hammer having a main handle and an auxiliary handle is disclosed, for example, in Japanese non-examined laid-open Patent Publication No. 59-47171.
In the above-mentioned known hammer, the main handle is disposed at the rear of the power tool body, and a detachable auxiliary handle is disposed on the front end side (the hammer bit side) of the power tool body. The auxiliary handle is additionally provided with a vibration-proofing structure in order to reduce transmission of vibration from the power tool body to the auxiliary handle.
In some hammer drills which can be appropriately switched between a hammering operation mode in which only a striking force in the axial direction is applied to a hammer bit and a hammer drill operation mode in which a striking force in the axial direction and a rotating force in the circumferential direction are applied to the hammer bit, a D-shaped auxiliary handle suitable for use in hammering operation and a bar-shaped auxiliary handle suitable for use in hammer drill operation are provided and the two auxiliary handles can be used according to the operation modes.
The detachable auxiliary handle of the above-mentioned known hammer has a vibration-proofing structure in itself. Therefore, as described above, in the case of a power tool in which the auxiliary handles can be used according to the operation modes, each of the auxiliary handles is additionally provided with a vibration-proofing structure, so that the manufacturing costs increase. Therefore, further improvement is required in this point.